Internal combustion engine



Feb. 7, 1933. H. v. HONN INTERNAL COMBUSTION ENGINE Filed Oct. 4, 1930 INVENTOR, HARLAN VERNE HONN. y 4

ATTORNEY Patented Feb. 7, 1933 PATENT OFFICE HABLAN VERNE HONN, OF SAN FRANCISCO, CALIFORNIA INTERNAL COMBUSTION ENGINE Application filed October 4, 1930. Serial No. 486,406.

My invention relates to internal combustion engines, and particularly to engines adapted for burning the heavier types of fuel 01 s.

' Among the objects of my invention are: First, to provide a heavy oil engine which may be operated at hi h s (1; second, to provide an engine suita le if: aircraft propulsion; third, to rovide an engine wherein o no electrical ignition system is required;

fourth, to provide an engine combining many of the advantages of the Diesel and Otto cycles; fifth, to provide a heavy oil engine, in which no carburetor is used, and in which the charges of fuel may be accuratel metered; and sixth, to provide a new met 0d of operating an internal combustion engine, which is applicable to engines operating upon either moderate or high compression.

Other objects of myinvention-will be apparent or will be specifically pointed out in the description forming a part of this specification, but I do not limit myself to the embodiment of my invention herein described, as various forms may be adopted within the sco of the claims.

ferring to the drawing: Figure 1 is a transverse sectional view through one cylinder of an internal combustion engine embodyin my invention. 7

Figure 2 is a detai ed section on a larger scale showin the fuel compression ump and injection vaFve as used in the engine shown in Figure 1.-

In generally descriptive terms, the engine of my invention preferably comprises the usual type of cylinder and piston, together with inlet and exhaust valves, such as are used in ordinary four-stroke-cycle gas engine practice. No carburetor is provided, however, the inlet valve preferably admitting only air to the cylinder. Timed with the piston, 1s a fuel pump which is capable of operating at pressures greatly in excess of those developed within the engine cylinder. This fuel pump is fed with a mixture of fuel and air, the amount of air bein much less than that required properly to urn the fuel. This mixture is preferably a froth formed from a heavy type of oil into which the required amount of air has been beaten. The pump is arranged to compress this mixture to such a degree that the heat of compression causes its ignition, the compression occurring simultaneously with the compression stroke within the engine cylinder. Means are provided for injecting the ignited fuel into the highly compressed air within the cylinder, with the result that the expanding gases within the froth disseminate the fuel throughout the combustion chamber, where it combines with the air in the cylinder at a speed which corresponds more closely towthe speed'of explosion in a gasoline engine than with the usual Diesel type of combustion.

The engine embodying'my invention comprises a cylinder 10 within which reciprocates the trunk type piston 11, joined b the usual connecting rod 12 to the era 13. The cylinder is provided with a removable cylinder head 15, within which are mounted t e valves, only the intake valve 16 being shown. Both the cylinder and the cylinder head are provided with water passages 17 and 18 respectively.

The valves are operated by rocker arms 20, actuated by push rods 21 from the cam shaft 22 in the usual manner. This structure is indicated only, since it is well known in the art, and since the functioning of my invention does not depend upon any particular valve or piston arrangement.

' Projecting into the side of the cylinder wall, in a position customarily occupied by the s arkcplugs, is the injecting nozzle 23 of a uel pump 25. The fuel pump is operated from the cam shaft 22 by ineans of a cam 26, and is timed so that its pressure stroke occurs substantially simultaneously with the compression stroke of the engine. The pump comprises a iston 27, which is drawn to the lower end 0 the pump cylinder by a spring 28, and which is actuated on its lip-stroke from the cam 26 by the push rod 30. The pump is constructed so that extremely small clearance is left at the end of the stroke of the piston, and since the bore of the cylinder is small, velv high pressures can be generated. The pump discharges through a port31,

which expands into a conical seat 32 for receiving a valve 33. A number of passages 34 are formed in the conical face of the valve, and' join in a passage 35 which extends through the nozzle 23. The valve is normally held against the seat by a light spring 36, which presses against a flat face 37 of the valve, and which is also exposed to the pressure within the cylinder 10, tending to hold the valve closed.

When the valve is seated, only the small end of its conical face is exposed to the pressure from within the pump, so that the net force acting on the valve is relatively small and the pressure from without will keep it from opening. The instant it starts to lift, however, its entire conical face is exposed to the pump pressure, causing it to open very rapidly, and permitting the ejection of the pump cylinder contents through the passages 34 and 35.

As will be described below, the charge delivered through the nozzle is already ignited, and thematerial of the valve should therefore be such as will withstand the erosion of fast moving fluids at high temperatures. Nitrided steel, carbolloy, or refractories such as lava or sillimanite are suitable for this purpose.

Means are provided forf-orming a froth from the fuel which is fed to the pump. This frothing mechanism may be a pump of the pressure blower type, having a cylindrical casing 40 within which is eccentrically mounted a cylindrical rotor 41 which is provided with vanes 42 pressing outwardly contact with the walls of the casing. 11 inlet pipe 43 admits air into the casing, while fuel oil, in small quantities, is forced under pressure through a second inlet duct 44. An outlet duct 45communicates with the injection pump25.

The amount-of air taken by pump is, with the output which can be furnished by the blower. The result is that a high pressure is built u ahead of the vanes-42, and the air, there ore, blows back beneath the vanes, forming bubbles from the oil film which they carry The result is an extremely tenacious froth, formed of very fine bubbles, and this froth is delivered through the outlet pipe. The same action will take place if the fuel oil be admitted through the air duct 43, but the form shown has certain advantages in practice, as admitting ofmore accurate metering of the fuel, which controls the size of the air bubbles and the proporions of oil and air in the froth.

The frother is shown as driven from the cam shaft 22 by suitable gearing 45. It is to be noted, however, that the action of the frother bears no relation to the engine cycle, and it is therefore possible to drive it from a separate motor, which may be a small electhe injection into of course, very small, as comparedtric motor, if desired. This method of drive has certain advantages in starting the engine initially.

In the preferred method of operation, the inlet valve 16 opens on the suction stroke of the engine, to admit pure air into the cylinder, which compresses it on the succeeding stroke. Simultaneously, the injection pump compresses a charge of the frothed fuel. The pressure developed within the'injection pump may be extremely high, heating the gas inclusions within the fuel to the ignition point.

When ignition takes place, a great increase in pressure within the pump occurs, lifting the valve 32, and allowing the charge of fuel, already ignited, to blow itself into the highly com ressed gas in the cylinder.

T e air included in the froth is insuflicient to support the combustion of more than a very small proportion of the fuel, but this air is so thoroughly intermingled with the fuel, that its expansion into the more lightly compressed gas in the cylinder diffuses the fuel throughout the cylinder, where combustion takes place as in the ordinary Diesel engine, but at a considerably higher speed. This speed may, if desired, be considerably accelerated by carburetting the air drawn into the cylinder to provide an extremely lean mixture, which will not explode under compression alone, but which will propagate the explosion due to the sprayed-in ignited fuel with great rapidity.

The preferred method of'operating an engine in accordance with my invention contemplates the use of pressures intermediate between those used in ordinary gasoline engine practice, and those used in Diesel practice. By the use of such pressures, some of the principal difficulties of Diesel engine construction and operation are avoided, while relatively high efficiencies are maintained. The method is not limited, however, to these intermediate pressures. Satisfactory operation may be had using compressions not exceeding those customary in gasoline engine operation, and, on the other hand, pressures directly com arable to those used in the ordinary type 0 Diesel engine may be obtained if desired. In the latter case, the principal advanta e of my method of operation lies in the quic er propagation of the combustion within the cylinder, and the consequent higher speed obtainable with'the engine.

While I have indicated in the drawing an engine of the in-line type used in automobile practice, it will at once be evident that one of the principal advantages-obtainable with my invention lies in its adaptability to aircraft use. Motors of the radial type may be converted from gasoline operation to heavy oil operation by a very simple change, involving merely the substitution of the injection pump for one of the customary spark plugs, and the provision of a single frot'hei' or beater for frothing the fuel which is fed to all of the cylinders.

I claim: 1. The method of igniting a liquid fuel which comprises forming afroth thereof with a combustion supporting gas, and compressing said froth to cause ignltion from the heat of compression of saidgas. 2. The method of igniting a liquid fuel which comprises forming a froth thereof with an i'nsufiicient quantity of combustion supporting gas to consume said fuel completely, and compressin said froth to cause ignition from the heat 0 compression of said as.

3. The method of operating an internal combustion engine with liquid fuel which comprises'the steps forming a froth of said fuel, compressing a charge of said froth to cause its lgnition from the heat of compression of the included gas, and inecting the i nited fuel into the combustion c amber of t e engine.

4. The method of o ratin an internal combustion engine wit liqui fuel which comprises the steps of mixing the fuel with air to form gaseous inclusions within the still-liquid fuel compressing the mixture to cause ignition from the heat of compression of the included air, and injecting the ignited mixture into the combustion chamber of the engine.

5. The method of 0 rating an internal combustion engine with liquid fuel which comprises the steps forming a froth of said fuel, compressing a charge of said froth to cause its ignition from the heat of compression of the included gas, sep ing a charge of air, and in ecting the ignited fuel into said compressed air.

6. In an internal combustion engine having a combustion chamber, means for compressing a frothed fuel to cause ignition thereof, means timed with said fuel compressing means for comp air within the combustion chamber, and means for releasing {2e ignited fuel into said'combustion chamr. V 7 In an internal combustion en e having a combustion chamber means or introducing air inclusions within a liquid fuel, means for compressin .said fuel to cause ignition thereof from the eat of com ression of theincluded air, means timed wi compressin means for compressing air within the com ustion chamber; and means for releasing the ignited fuel into said combustion chamber.

8. In combination with aninternal combustion engine, means for forming a froth from a liquid fuel, means for comp 1 said froth to cause ignition thereof, an means for injectingthe ignited froth into the engine.

9. In combination with an internal combustion engine having a cylinder, means for said fuel.

frothing a fuel, a pump ha a piston for compressing said fuel to cause ignition there- .of, and means comprising an outlet valve for said pump for admitting the ignited fuel to said cylinder upon the risein pressure due to its ignition.

10. In combination withan internal combustion engine having a cylinder, means for frothing afuel, a pump havi a piston for compressing said fuel to cause 1 'tion thereof, and an outlet valve for sai pump comprising a conical valve seat hav' a port in the apex thereof, and a conical v ifive engaging said seat, said valve having open in its conical face to permit the passage ti f fuel therethrough.

In testimony whereof, I have hereunto set my hand.

, HARLAN VERNE HONN.

arately compress- 

